4 files changed, 162 insertions, 14 deletions

diff --git a/src/arch/avx2.h b/src/arch/avx2.h
index 24c8280..3fb46c9 100644
--- a/src/arch/avx2.h
+++ b/src/arch/avx2.h
@@ -24,9 +24,9 @@
 #define ZERO_CUBE _mm256_set_epi64x(0, 0, 0, 0)
 #define SOLVED_CUBE _mm256_set_epi64x(SOLVED_H, SOLVED_L, 0, SOLVED_L)
 
-
-STATIC_INLINE uint64_t permtoindex_8x8(int64_t);
+STATIC_INLINE uint64_t permtoindex_Nx8(uint64_t, int64_t);
 STATIC_INLINE int64_t indextoperm_8x8(uint64_t);
+STATIC_INLINE int64_t indextoperm_4x8(uint64_t);
 
 STATIC_INLINE int
 popcount_u32(uint32_t x)
@@ -295,17 +295,17 @@ set_eo(cube_t cube[static 1], uint64_t eo)
 }
 
 STATIC_INLINE uint64_t
-permtoindex_8x8(int64_t a)
+permtoindex_Nx8(uint64_t n, int64_t a)
 {
         uint64_t i, c, ret;
         __m64 cmp;
 
-        for (i = 0, ret = 0; i < 8; i++) {
+        for (i = 0, ret = 0; i < n; i++) {
                 cmp = _mm_set1_pi8(a & INT64_C(0xFF));
                 a = (a >> INT64_C(8)) | INT64_C(0x0F00000000000000);
                 cmp = _mm_cmpgt_pi8(cmp, _mm_cvtsi64_m64(a));
                 c = _mm_popcnt_u64(_mm_cvtm64_si64(cmp)) >> UINT64_C(3);
-                ret += c * factorial[7-i];
+                ret += c * factorial[n-1-i];
         }
 
         return ret;
@@ -332,6 +332,39 @@ indextoperm_8x8(uint64_t p)
         return ret;
 }
 
+STATIC_INLINE int64_t
+indextoperm_4x8(uint64_t p)
+{
+        static const int64_t A[FACT_4] = {
+                [0] = INT64_C(0x03020100),
+                [1] = INT64_C(0x02030100),
+                [2] = INT64_C(0x03010200),
+                [3] = INT64_C(0x01030200),
+                [4] = INT64_C(0x02010300),
+                [5] = INT64_C(0x01020300),
+                [6] = INT64_C(0x03020001),
+                [7] = INT64_C(0x02030001),
+                [8] = INT64_C(0x03000201),
+                [9] = INT64_C(0x00030201),
+                [10] = INT64_C(0x02000301),
+                [11] = INT64_C(0x00020301),
+                [12] = INT64_C(0x03010002),
+                [13] = INT64_C(0x01030002),
+                [14] = INT64_C(0x03000102),
+                [15] = INT64_C(0x00030102),
+                [16] = INT64_C(0x01000302),
+                [17] = INT64_C(0x00010302),
+                [18] = INT64_C(0x02010003),
+                [19] = INT64_C(0x01020003),
+                [20] = INT64_C(0x02000103),
+                [21] = INT64_C(0x00020103),
+                [22] = INT64_C(0x01000203),
+                [23] = INT64_C(0x00010203),
+        };
+
+        return A[p];
+}
+
 STATIC_INLINE uint64_t
 coord_cp(cube_t cube)
 {
@@ -341,7 +374,7 @@ coord_cp(cube_t cube)
         cp = _mm256_and_si256(cube, CP_AVX2);
         _mm256_storeu_si256((__m256i_u *)aux, cp);
 
-        return permtoindex_8x8(aux[0]);
+        return permtoindex_Nx8(8, aux[0]);
 }
 
 STATIC_INLINE cube_t
@@ -359,7 +392,7 @@ coord_epud(cube_t cube)
         ep = _mm256_and_si256(cube, EP_AVX2);
         _mm256_storeu_si256((__m256i_u *)aux, ep);
 
-        return permtoindex_8x8(aux[2]);
+        return permtoindex_Nx8(8, aux[2]);
 }
 
 STATIC_INLINE cube_t
@@ -367,3 +400,29 @@ invcoord_epud(uint64_t i)
 {
         return _mm256_set_epi64x(SOLVED_H, indextoperm_8x8(i), 0, SOLVED_L);
 }
+
+STATIC_INLINE uint64_t
+coord_epe(cube_t cube)
+{
+        cube_t ep;
+        int64_t aux[4];
+
+        ep = _mm256_and_si256(cube, EP_AVX2);
+        ep = _mm256_xor_si256(ep, _mm256_set1_epi8(8));
+        _mm256_storeu_si256((__m256i_u *)aux, ep);
+
+        return permtoindex_Nx8(4, aux[3]);
+}
+
+STATIC_INLINE cube_t
+invcoord_epe(uint64_t i)
+{
+        int64_t a;
+        __m64 a64;
+
+        a = indextoperm_4x8(i);
+        a64 = _mm_add_pi8(_mm_cvtsi64_m64(a), _mm_set_pi32(0, 0x08080808));
+        a = _mm_cvtm64_si64(a64);
+
+        return _mm256_set_epi64x(a, SOLVED_L, 0, SOLVED_L);
+}
diff --git a/src/arch/common.h b/src/arch/common.h
index 6c62a2e..1c8c0b0 100644
--- a/src/arch/common.h
+++ b/src/arch/common.h
@@ -41,6 +41,8 @@ STATIC_INLINE uint64_t coord_cp(cube_t);
 STATIC_INLINE cube_t invcoord_cp(uint64_t);
 STATIC_INLINE uint64_t coord_epud(cube_t);
 STATIC_INLINE cube_t invcoord_epud(uint64_t);
+STATIC_INLINE uint64_t coord_epe(cube_t);
+STATIC_INLINE cube_t invcoord_epe(uint64_t);
 
 STATIC_INLINE void
 invcoord_esep_array(uint64_t set1, uint64_t set2, uint8_t mem[static 12])
diff --git a/src/arch/neon.h b/src/arch/neon.h
index fef6220..5723b60 100644
--- a/src/arch/neon.h
+++ b/src/arch/neon.h
@@ -1,6 +1,6 @@
 #define CO2_NEON vdup_n_u8(0x60)
 #define COCW_NEON vdup_n_u8(0x20)
-#define PBITS8_NEON vdup_n_u8(0x07)
+#define PBITS8_NEON vdup_n_u8(PBITS)
 
 STATIC_INLINE uint8x16_t compose_edges_slim(uint8x16_t, uint8x16_t);
 STATIC_INLINE uint8x8_t compose_corners_slim(uint8x8_t, uint8x8_t);
@@ -29,8 +29,9 @@ STATIC_INLINE uint8x8_t compose_corners_slim(uint8x8_t, uint8x8_t);
 const uint8_t SOLVED_L[8] = {0, 1, 2, 3, 4, 5, 6, 7};
 const uint8_t SOLVED_H[8] = {8, 9, 10, 11, 0, 0, 0};
 
-STATIC_INLINE uint64_t permtoindex_8x8(uint8x8_t);
+STATIC_INLINE uint64_t permtoindex_Nx8(uint64_t, uint8x8_t);
 STATIC_INLINE uint8x8_t indextoperm_8x8(uint64_t);
+STATIC_INLINE uint8x8_t indextoperm_4x8(uint64_t);
 
 STATIC_INLINE int
 popcount_u32(uint32_t x)
@@ -364,14 +365,14 @@ invcoord_esep(uint64_t esep)
 }
 
 STATIC_INLINE uint64_t
-permtoindex_8x8(uint8x8_t a)
+permtoindex_Nx8(uint64_t n, uint8x8_t a)
 {
         uint64_t i, c, ret;
         uint8x8_t cmp;
         uint64x1_t anum;
         uint8_t or[8] = {0, 0, 0, 0, 0, 0, 0, 0x0F};
 
-        for (i = 0, ret = 0; i < 8; i++) {
+        for (i = 0, ret = 0; i < n; i++) {
                 cmp = vdup_lane_u8(a, 0);
                 anum = vreinterpret_u64_u8(a);
                 anum = vshr_n_u64(anum, 8);
@@ -379,7 +380,7 @@ permtoindex_8x8(uint8x8_t a)
                 a = vorr_u8(a, vld1_u8(or));
                 cmp = vcgt_u8(cmp, a);
                 c = vaddv_u8(vshr_n_u8(cmp, 7));
-                ret += c * factorial[7-i];
+                ret += c * factorial[n-1-i];
         }
 
         return ret;
@@ -407,10 +408,43 @@ indextoperm_8x8(uint64_t p)
         return vld1_u8(ret);
 }
 
+STATIC_INLINE uint8x8_t
+indextoperm_4x8(uint64_t p)
+{
+        static const int64_t A[FACT_4] = {
+                [0] = UINT64_C(0x03020100),
+                [1] = UINT64_C(0x02030100),
+                [2] = UINT64_C(0x03010200),
+                [3] = UINT64_C(0x01030200),
+                [4] = UINT64_C(0x02010300),
+                [5] = UINT64_C(0x01020300),
+                [6] = UINT64_C(0x03020001),
+                [7] = UINT64_C(0x02030001),
+                [8] = UINT64_C(0x03000201),
+                [9] = UINT64_C(0x00030201),
+                [10] = UINT64_C(0x02000301),
+                [11] = UINT64_C(0x00020301),
+                [12] = UINT64_C(0x03010002),
+                [13] = UINT64_C(0x01030002),
+                [14] = UINT64_C(0x03000102),
+                [15] = UINT64_C(0x00030102),
+                [16] = UINT64_C(0x01000302),
+                [17] = UINT64_C(0x00010302),
+                [18] = UINT64_C(0x02010003),
+                [19] = UINT64_C(0x01020003),
+                [20] = UINT64_C(0x02000103),
+                [21] = UINT64_C(0x00020103),
+                [22] = UINT64_C(0x01000203),
+                [23] = UINT64_C(0x00010203),
+        };
+
+        return vreinterpret_u8_u64(vdup_n_u64(A[p]));
+}
+
 STATIC_INLINE uint64_t
 coord_cp(cube_t cube)
 {
-        return permtoindex_8x8(vand_u8(cube.corner, PBITS8_NEON));
+        return permtoindex_Nx8(8, vand_u8(cube.corner, PBITS8_NEON));
 }
 
 STATIC_INLINE cube_t
@@ -425,7 +459,12 @@ invcoord_cp(uint64_t i)
 STATIC_INLINE uint64_t
 coord_epud(cube_t cube)
 {
-        return permtoindex_8x8(vand_u8(vget_low_u8(cube.edge), PBITS8_NEON));
+        uint8x8_t a;
+
+        a = vget_low_u8(cube.edge);
+        a = vand_u8(a, PBITS8_NEON);
+
+        return permtoindex_Nx8(8, a);
 }
 
 STATIC_INLINE cube_t
@@ -436,3 +475,29 @@ invcoord_epud(uint64_t i)
                 .edge = vcombine_u8(indextoperm_8x8(i), vld1_u8(SOLVED_H))
         };
 }
+
+STATIC_INLINE uint64_t
+coord_epe(cube_t cube)
+{
+        uint8x8_t a;
+
+        a = vget_high_u8(cube.edge);
+        a = vand_u8(a, PBITS8_NEON);
+        a = veor_u8(a, vdup_n_u8(8));
+
+        return permtoindex_Nx8(4, a);
+}
+
+STATIC_INLINE cube_t
+invcoord_epe(uint64_t i)
+{
+        uint8x8_t a;
+
+        a = indextoperm_4x8(i);
+        a = vadd_u8(a, vreinterpret_u8_u64(vdup_n_u64(UINT64_C(0x08080808))));
+
+        return (cube_t) {
+                .corner = vld1_u8(SOLVED_L),
+                .edge = vcombine_u8(vld1_u8(SOLVED_L), a)
+        };
+}
diff --git a/src/arch/portable.h b/src/arch/portable.h
index 5acccf2..26001ee 100644
--- a/src/arch/portable.h
+++ b/src/arch/portable.h
@@ -334,3 +334,25 @@ invcoord_epud(uint64_t i)
         return STATIC_CUBE(0, 1, 2, 3, 4, 5, 6, 7,
             e[0], e[1], e[2], e[3], e[4], e[5], e[6], e[7], 8, 9, 10, 11);
 }
+
+STATIC_INLINE uint64_t
+coord_epe(cube_t cube)
+{
+        int i;
+
+        for (i = 8; i < 12; i++)
+                cube.edge[i] = (cube.edge[i] & PBITS) - 8;
+
+        return permtoindex(4, cube.edge+8);
+}
+
+STATIC_INLINE cube_t
+invcoord_epe(uint64_t i)
+{
+        uint8_t e[4];
+
+        indextoperm(i, 4, e);
+
+        return STATIC_CUBE(0, 1, 2, 3, 4, 5, 6, 7,
+            0, 1, 2, 3, 4, 5, 6, 7, e[0]+8, e[1]+8, e[2]+8, e[3]+8);
+}